This invention relates to bearings in which there is a housing having an opening to receive a bearing unit or cartridge comprising at least inner and outer races and anti-friction means or rolling elements therebetween in contact with inner and outer raceways on the races. There is a need to supply lubricant to the anti-friction means, such as balls or rollers, and to effectuate the supply, there is provided a passageway through the housing into which an exterior lubricant fitting or nipple is received and the bearing unit is constructed with an opening or passage to permit the passage of lubricant introduced at the fitting to pass through the passageway and through the bearing unit opening or passage into the interior of the bearing unit to the anti-friction means or rolling elements.
Geometric inaccuracies between the housing and the bearing unit can result in lubricant leakage, and at times, may be such to cause inadequate lubrication of the rolling elements of the bearing.